Multiple boom deployment

ABSTRACT

Some embodiments of the invention include a boom deployment system. The boom deployment system, for example, may include a housing, a spool, a first boom, and a second boom. The spool may be disposed within the housing and configured to rotate around an axis that is fixed relative to the housing. The first boom and/or the second boom may have a cylindrical shape in a deployed configuration, a flattened shape in a stowed configuration, and a slit that extends along the longitudinal length of the boom in the deployed configuration. The first boom and/or the second boom may be stowed in the stowed configuration flattened and wrapped around the spool. The first boom and/or the second boom may transition from the stowed configuration to the deployed configuration as the spool rotates around the axis.

GOVERNMENT RIGHTS

This invention was made with government support under contract numberNNX15CG38P awarded by the National Aeronautics and Space Administration(NASA). The government has certain rights in the invention.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a non-provisional of U.S. Provisional PatentApplication No. 62/150,965, filed Apr. 22, 2015, titled MULTIPLE BOOMDEPLOYMENT.

SUMMARY

Some embodiments of the invention include a multi-boom deployment devicethat includes a first spool, a first boom, a second boom, a third boom,and a fourth boom. The first boom having a cylindrical shape in adeployed configuration, a flattened shape in a stowed configuration, anda slit that extends along the longitudinal length of the first boom inthe deployed configuration. In some embodiments, the first boom isstowed in the stowed configuration flattened and wrapped around thefirst spool. The second boom having a cylindrical shape in a deployedconfiguration, a flattened shape in a stowed configuration, and a slitthat extends along the longitudinal length of the second boom in thedeployed configuration. In some embodiments, the second boom is stowedin the stowed configuration flattened and wrapped around the firstspool. The third boom having a cylindrical shape in a deployedconfiguration, a flattened shape in a stowed configuration, and a slitthat extends along the longitudinal length of the third boom in thedeployed configuration. In some embodiments, the third boom is stowed inthe stowed configuration flattened and wrapped around the first spool.The fourth boom having a cylindrical shape in a deployed configuration,a flattened shape in a stowed configuration, and a slit that extendsalong the longitudinal length of the fourth boom in the deployedconfiguration. In some embodiments, the fourth boom is stowed in thestowed configuration flattened and wrapped around the first spool.

In some embodiments, the multi-boom deployment device may include ahousing within which the first spool, the first boom, the second boom,the third boom, and the fourth boom are disposed in the stowed thestowed configuration.

In some embodiments, the multi-boom deployment device may include ahousing having an aperture through which the first boom extends in thedeployed configuration.

In some embodiments, the multi-boom deployment device may include arestraint mechanism configured to cover the aperture in the stowedconfiguration and open in the deployed configuration.

In some embodiments, the multi-boom deployment device may include ahousing and a first root lock. In some embodiments, the first spool isdisposed within the housing. In some embodiments, the first root lockmay be disposed within the housing. In some embodiments, the root lockis position within the housing relative to the spool, wherein in thedeployed configuration a proximal end of the first boom is wrappedaround the root lock.

In some embodiments, the multi-boom deployment device may include aspring mechanism coupled with the housing and the first root lock. Insome embodiments, the spring mechanism is configured to move the rootlock from a location in the stowed configuration into a position nearthe spool in the deployed configuration.

In some embodiments, the first boom and one or more of the second boom,the third boom, and the fourth boom are substantially orthogonal in thedeployed configuration.

In some embodiments, the first boom and at least one of the second boom,the third boom, and the fourth boom are substantially parallel in thedeployed configuration.

In some embodiments, the first boom transitions from the stowedconfiguration to the deployed configuration as the spool rotates aroundthe axis, and wherein the second boom transitions from the stowedconfiguration to the deployed configuration as the spool rotates aroundthe axis.

In some embodiments, the multi-boom deployment device may include ahousing, wherein the first spool is disposed within the housing; asecond spool disposed within the housing; and a fifth boom having acylindrical shape in a deployed configuration, a flattened shape in astowed configuration, and a slit that extends along the longitudinallength of the boom in the deployed configuration, wherein the fifth boomis stowed in the stowed configuration flattened and wrapped around thesecond spool.

Some embodiments of the invention include a boom deployment system. Theboom deployment system, for example, may include a housing, a spool, afirst boom, and a second boom. The spool may be disposed within thehousing and configured to rotate around an axis that is fixed relativeto the housing. The first boom and/or the second boom may have acylindrical shape in a deployed configuration, a flattened shape in astowed configuration, and a slit that extends along the longitudinallength of the boom in the deployed configuration. The first boom and/orthe second boom may be stowed in the stowed configuration flattened andwrapped around the spool. The first boom and/or the second boom maytransition from the stowed configuration to the deployed configurationas the spool rotates around the axis.

In some embodiments, the boom deployment system may include a firstsensor coupled with the first boom and a second sensor coupled with thesecond boom.

In some embodiments, the boom deployment system may include a first wirecoupled with the first boom and a second wire coupled with the secondboom.

In some embodiments, in the deployed configuration the first boom issubstantially perpendicular with the second boom.

In some embodiments, in the deployed configuration the first boom issubstantially parallel with the second boom.

In some embodiments, the housing includes a first aperture through whichthe first boom extends in the deployed configuration, and wherein thehousing includes a second aperture through which the second boom extendsin the deployed configuration.

Some embodiments may include a satellite having a housing, a first spooldisposed within the housing and configured to rotate around an axis thatis fixed relative to the housing; and a first boom having a cylindricalshape in a deployed configuration, a flattened shape in a stowedconfiguration, and a slit that extends along the longitudinal length ofthe first boom in the deployed configuration, wherein the first boom isstowed in the stowed configuration flattened and wrapped around thefirst spool, the first boom transitions from the stowed configuration tothe deployed configuration as the spool rotates around the axis; asecond boom having a cylindrical shape in a deployed configuration, aflattened shape in a stowed configuration, and a slit that extends alongthe longitudinal length of the second boom in the deployedconfiguration, wherein the second boom is stowed in the stowedconfiguration flattened and wrapped around the first spool the secondboom transitions from the stowed configuration to the deployedconfiguration as the spool rotates around the axis; a second spooldisposed within the housing and configured to rotate around an axis thatis fixed relative to the housing; and a third boom having a cylindricalshape in a deployed configuration, a flattened shape in a stowedconfiguration, and a slit that extends along the longitudinal length ofthe third boom in the deployed configuration, wherein the third boom isstowed in the stowed configuration flattened and wrapped around thesecond spool, the third boom transitions from the stowed configurationto the deployed configuration as the second spool rotates around theaxis.

In some embodiments, in the deployed configuration the third boom issubstantially perpendicular with the second boom, and wherein in thedeployed configuration the third boom is substantially perpendicularwith the first boom.

In some embodiments, the satellite may include a first restraintmechanism configured to cover an aperture in the housing in the stowedconfiguration and open in the deployed configuration, wherein the thirdboom extends through the aperture in the deployed configuration.

In some embodiments, the satellite may include a first root plugdisposed to couple with the first boom in the deployed configuration; asecond root plug disposed to couple with the second boom in the deployedconfiguration; and a third root plug disposed to couple with the thirdboom in the deployed configuration.

BRIEF DESCRIPTION OF THE FIGURES

These and other features, aspects, and advantages of the presentdisclosure are better understood when the following Detailed Descriptionis read with reference to the accompanying drawings.

FIG. 1 illustrates a satellite with booms in a stowed configurationaccording to some embodiments.

FIG. 2 illustrates a satellite with booms in a deployed configurationaccording to some embodiments.

FIG. 3 illustrates an example boom according to some embodiments.

FIG. 4 illustrates a multi-boom deployment device in a stowedconfiguration according to some embodiments.

FIG. 5 illustrates a multi-boom deployment device in apartially-deployed configuration according to some embodiments.

FIG. 6 illustrates a multi-boom deployment device in a mostly-deployedconfiguration according to some embodiments.

FIG. 7 illustrates a multi-boom deployment device in a deployedconfiguration according to some embodiments.

FIG. 8 is a side view of a multi-boom deployment device according tosome embodiments.

FIG. 9 illustrates a single-boom deployment device in a stowedconfiguration according to some embodiments.

FIG. 10 illustrates a single-boom deployment device in a mostly-stowedconfiguration according to some embodiments.

FIG. 11 illustrates a single-boom deployment device in a mostly-deployedconfiguration according to some embodiments.

FIG. 12 illustrates a single-boom deployment device in a deployedconfiguration according to some embodiments.

FIG. 13A illustrates a single-boom deployment device in a deployedstate.

FIG. 13B illustrates a single-boom deployment device in the deployedstate.

FIG. 14A illustrates a plurality of teeth along the length of the slitin an unlocked configuration.

FIG. 14B illustrates the plurality of teeth in a locked configuration.

FIG. 15A and FIG. 15B illustrate a slit-lock mechanism according to someembodiments.

FIG. 16 illustrates a single-boom deployment device in a stowedconfiguration according to some embodiments.

FIG. 17 illustrates the single-boom deployment device in apartially-deployed configuration according to some embodiments.

FIG. 18 illustrates the single-boom deployment device in a deployedconfiguration according to some embodiments.

FIG. 19A and FIG. 19B illustrate an example embodiment of a distal endof a boom.

FIG. 20 illustrates the relationship between the solar flux incidentalong a boom and the resulting “thermal bending” on the boom accordingto some embodiments.

DETAILED DESCRIPTION

Some embodiments of the invention include a multi-boom deployment deviceand a single-boom deployment device. Some embodiments may also includevarious satellite systems that include one or more multi-boom deploymentdevices and/or one or more single-boom deployment devices. In someembodiments, the multi-boom deployment device may include a plurality ofbooms that are flattened and wrapped around a spool within a housing ina stowed configuration. In some embodiments, in a deployed configurationthe booms may extend away from the housing a plurality of directions.The multi-boom deployment device and/or the single-boom deploymentdevice may be used for any number of purposes.

Some embodiments may be used for measuring electric fields, which mayinclude the measurement of voltage potential between three pairs ofelectrodes separated along orthogonal axes using the booms.

In some embodiments, the satellite system may deploy two, three, four,or more booms from a single deployment mechanism or deployment drum orspool. Each boom may, for example, include a tubular longeron with aslit along the length of the longeron that may or may not include teethon one or more sides of the longeron. In some embodiments, six booms maybe deployed using as few as two or three deployment mechanisms ordeployment drums or spools. In some embodiments, the longeron may beflattened and/or rolled along the longitudinal length of the longeronsuch as, for example, for stowage. In some embodiments, the longeron mayinclude teeth along the length of the slit such that the teeth can jointogether after deployment.

FIG. 1 illustrates a satellite 100, which may include a satellite body105 according to some embodiments. In some embodiments, the satellite100 may include a plurality of boom deployment devices such as, forexample, a multi-boom deployment device 110 and/or two single-boomdeployment devices 115.

In some embodiments, some components of the satellite 100 may beconfigured to be packaged within a small volume such as, for example, abox or the volume of a satellite body 105. In some embodiments, thesatellite body 105 may be configured to include any number of otherdevices within the volume of the satellite body 105, such as, forexample: a 3-axis electric field sensor, a 3D vector electric fieldinstrument, a magnetometer, particle detector, Langmuir probe, an iondrift meter, a flux gate magnetometer, electrostatic analyzer, apropulsion system, a controller, communication systems, or any otherdesirable device to be housed within the satellite body 105. In someembodiments, spacecraft functionality for the satellite body 105 may beprovided by a satellite bus such as the XB-1 Precision Pointing XACTBased satellite bus or any other satellite bus configured to performfunctions such as ADCS, C+DH, Power, RF/Comm, GPS or 3-axis stabilizedcapability.

In some embodiments, various science objectives can be met usingmultiple satellites in Low Earth Orbit (LEO) that include 3-axiselectric field instruments. One such deployment system may include anElectric Potential and Field Instrument for a satellite that can beaccommodated in less than half of a 6U satellite. In some embodiments,this may include a deployable composite boom technology withlightweight, stiff, straight, thermally stable booms capable of beingstowed within a satellite form factor. In some embodiments, a satellitemay include one or more deployable booms with lengths configured toaccomplish satellite missions.

In some embodiments, in the stowed configuration two or more booms maybe wrapped around the same drum or spool. In some embodiments, each boommay include a slit tube longeron comprising a slit that extends alongthe longitudinal length of the longeron. In some embodiments, thelongeron may be flattened and/or rolled along the longitudinal length ofthe longeron such as, for example, for stowage. In some embodiments, thelongeron may include teeth along the length of the slit such that theteeth can join together after deployment.

FIG. 2 illustrates a satellite 100 with booms 205 deployed. Thesatellite 100 may include internal electronics and spherical sensorsmounted on long rigid graphite composite booms coupled with the booms205. In some embodiments, such sensors may be configured to form threeorthogonal dipoles or to act individually depending upon the desiredmeasurement mode. The booms 205 may be composed of a sufficiently rigidmaterial, such as graphite for example, that enables the instrument tobe accommodated on a multi-axis stabilized satellite platform. In someembodiments the booms 205 may be configured to form any number of dipolelengths such as 4 m, 5 m, or any other length. Additionally, the booms205 may be configured to be deployable and retractable. The satellite100 may include any number of booms 205.

FIG. 3 illustrates an example boom 305 according to some embodiments.The boom 305 can be flattened and rolled for stowage and then regain itsoriginal, unflattened, circular, elliptical, or semi-circularcross-section during deployment. The boom 305 may include a long tubewith one or more slits 308 or gaps that extend through all or a portionof the longitudinal length of the boom 305. The boom 305 may include ahollow interior. The slit 308 may allow the boom 305 to be flattened androlled into a stowed or rolled configuration or extended in a deployedconfiguration. When rolled, various different booms may be stacked,nested, aligned and/or combined and collectively rolled together. Theboom 305 may be constructed from any type of material that may, forexample, include metal, graphite, fiber, resins, shape memory materials,composite materials, polymers, etc. In some embodiments, the boom 305may be constructed from a composite material with a number of pliesembedded with a resin.

The boom 305 may have a tubular shape in the deployed configuration andflattened and rolled in the stowed configuration. When rolling a boom305, the tubular cross-section of the boom 305 can be flattened and/orthe boom 305 may be opened along the longitudinal length of the boom305. The boom 305 can then be rolled into a stowed configuration. Insome embodiments, during stowage, portions of the boom 305 may beprogressively flattened as the boom 305 is rolled up. In someembodiments, multiple booms can be stacked upon one another, nested orembedded within each other in the tubular or deployed configuration. Thecombined boom stack can then be rolled along the longitudinal length ofthe booms into the stowed configuration.

In some embodiments, the boom 305 may include more than one slit alongthe longitudinal length of the boom 305.

FIG. 4 illustrates a multi-boom deployment device 400 in a stowedconfiguration according to some embodiments. The multi-boom deploymentdevice 400 may include stow and/or deploy any plurality of booms suchas, for example, two, three, four, five, six, seven, etc. booms.

The multi-boom deployment device 400 shown in FIG. 4 includes four boomsflattened and rolled about a spool 470. The four booms in this exampleinclude boom 410A, boom 410B, boom 410C, and boom 410D (collectivelyand/or individually boom 410). The booms 410 in the stowed configurationcomprise flattened and wound booms 475 that are wound about the spool 47o. Each boom 410 may, for example, be similar to boom 305 and/or mayinclude the characteristics and/or properties of boom 305.

In some embodiments, the spool 470 may include a motor such as, forexample, a stepper motor (e.g., the Faulhaber AM 0820 or the like). Insome embodiments, the motor may be disposed within the interior of thespool 470. In some embodiments, the motor may be used to drive out theboom 410.

In some embodiments, the boom 410 may include any of a variety ofdeployable composite booms that range from 12.7 mm (0.5″) to 203 mm(8.0″) diameter and up to 23 H meters (75-ft) in length. In someembodiments, the boom 410 may also include slit-tube composite boom thatcan be flattened and rolled around the spool 470 for storage. Someembodiments may include a boom 410 configured to be 1.5 m long, with a19 mm diameter motor-driven boom 410 that may take up less than 50% of a1U satellite volume and weighs less than 200 g.

In some embodiments, the boom 410 may be rotated using strain energystored in one or more of the booms. For example, while the booms 410 arebeing flattened and rolled into the stowed configuration strain energyis introduced into the booms 410. The strain energy, for example, canprovide a bias in the booms toward the deployed state. Thus, when arestraint mechanism holding the booms in place is released, the strainenergy in the booms 410 will cause the booms to unroll and deploy.Various other mechanisms may be used to unroll the booms 410 on thespool 470.

In some embodiments, the boom 410 may be configured to survive themechanical strain of being wrapped around the spool 470, while alsohaving sufficient axial stiffness and a coefficient of thermal expansion(“CTE”), allowing for tip stability in a typical on-orbit environment.In some embodiments, the size of the boom 410 and the sensor 415 may beconfigured to reduce shadowing and influences on electric fielddetection.

In some embodiments, the boom 410 may be configured to be sufficientlylong and narrow as to reduce the influence of the satellite 100 on a DCe-field vector measurement.

The booms 410 may be stowed within housing 480. The housing 480 maycomprise any geometric shape and/or may have any size configured to stowand/or deploy the booms 410. In this example, the housing comprise aroughly cube shape. In some embodiments, the housing may be disposedwithin a satellite or other body.

In some embodiments, each boom 410 may be coupled with a correspondingboom wire 465 (e.g., boom wire 465A, boom wire 465B, boom wire 465C,and/or boom wire 465C collectively and/or individually boom wire 465)and/or a corresponding sensor 415 (e.g., sensor 415A, sensor 415B,sensor 415C, and/or sensor 415C collectively and/or individually sensor415). The boom wire 465 may include any type of wire such as, forexample, wire that can communicate sensor data or signals from thesensor 415 to data sampling device. In some embodiments, the sensor 415may include an electric field sensor, a magnetic field sensor, atemperature sensor, etc.

The housing 480 may include a plurality of restraint mechanisms 405(e.g., restraint mechanism 405A, restraint mechanism 405B, restraintmechanism 405C, and/or restraint mechanism 405C collectively and/orrestraint mechanism 405).

In some embodiments, the restraint mechanisms 405 may be spring loadedso that when an electric release on the restraint mechanisms 405 isactivated, the restraint mechanisms may spring open as shown in FIG. 5.Each boom 410 may disposed near, include, and/or be associated with acorresponding restraint mechanism 405 such that the boom 410 maydeployed through the corresponding restraint mechanism 405 duringdeployment. The restraint mechanism 405 may include a spring loadeddevice held closed with any number of simple release devices, such as aburn wire. The restraint mechanism 405 may be further configured to bereleased by a single command from the satellite 100. The restraintmechanism may then be configured to pop open. In some embodiments, thesensor 415 may be configured to be released once the restraint mechanism405 has opened. In some embodiments, embodiments the restraint mechanismmay include a strap, cord, wire, latch, release, clamp, etc.

In the example shown in FIG. 4, the restraint mechanism 405 comprises adoor. In the stowed configuration, for example, the door may be closed.The closed doors, for example, may secure the boom 410 within thehousing. In some embodiments, the restraint mechanisms 405 may include asocket that is sized and/or configured to couple with the sensor 415,for example, to secure the sensor while in the stowed configuration.

In some embodiments, the multi-boom deployment device 400 may include aboom deployment guide that includes a first boom guide arm 420 (firstboom guide arm 420A, first boom guide arm 420B, first boom guide arm420C, and/or first boom guide arm 420D collectively and/or individuallyfirst boom guide arm 420), a second boom guide arm 421 (second boomguide arm 421A, second boom guide arm 421B, second boom guide arm 421C,and/or second boom guide arm 421D collectively and/or individually firstboom guide arm 421), and/or a boom guide cross member 435 (e.g., boomguide cross member 435A, boom guide cross member 435B, boom guide crossmember 435C, and/or boom guide cross member 435D collectively and/orindividually boom guide cross member 435). The boom guide arm 420 and/orthe boom guide arm 421 may be biased toward the flattened and woundbooms 475 on the spool 470. In some embodiments, each of the boomdeployment guides may include a plurality of rollers or wheels such as,for example, a first wheel 430 (e.g., first wheel 430A, first wheel430B, first wheel 430C, and/or first wheel 430D collectively and/orindividually first wheel 430) and/or a second wheel 431 (e.g., secondwheel 431A, second wheel 431B, second wheel 431C, and/or second wheel431D collectively and/or individually second wheel 431). In someembodiments, the boom deployment guides may guide a corresponding boomtoward an exit aperture of the housing 480 during deployment.

In some embodiments, the multi-boom deployment device 400 may include aplurality of root plugs 425 (e.g., root plugs 425A, root plugs 425B,root plugs 425C, and/or root plugs 425D collectively and/or individuallyroot plugs 425). Each boom 410 may couple with a corresponding root plug425 after deployment to secure the boom 410 with the housing 480 asshown in FIG. 7. In some embodiments, each root plug 425 may be coupledwith a spring mechanism 460. In some embodiments, the spring mechanism460 (e.g., spring mechanism 460A, spring mechanism 460B, springmechanism 460C, and/or spring mechanism 460D collectively and/orindividually spring mechanism 460) may be coupled with the housing 480.In some embodiments, the spring mechanism 460 may rotate the root plug425 into a position near the proximal end of the boom 410 so that theproximal end of the boom 410 may wrap around the root plug 425 whendeployed and formed into a cylindrical shape in the deployedconfiguration. In the stowed configuration, for example, the root plug425 may be positioned away from the spool 470 and/or the flattened andwound booms 475, and/or nearer the interior wall of the housing 480.

FIG. 5 illustrates a multi-boom deployment device 400 in apartially-deployed configuration according to some embodiments. In thisconfiguration, the booms are partially stowed within the housing. Forinstance, a portion of each boom 410 may still be wrapped around thespool 470. In this example, the restraint mechanisms 405 are open asshown in the figure. When the restraint mechanisms open an aperture inthe housing 480 is opened through which each of the booms maybedeployed. In this example, each of the four booms are beginning to exitthe housing 480 through the apertures. Also, in this configuration, thesensors 415 and/or the boom wires 465 have exited the housing 480through the apertures.

The spool 470, in this configuration, has been rotated clockwise to anew angular position in comparison to the angular position of the spool470 in FIG. 4. This rotation may cause the booms 410 to uncoil from thespool 470 and extend through the apertures in the housing 480. As thebooms 410 extend they unflatten and regain their tubular shape. As thebooms 410 roll off the spool 470 the distal end for the boom 410 may bedirected toward the aperture by the boom deployment guide.

FIG. 6 illustrates a multi-boom deployment device 400 in amostly-deployed configuration according to some embodiments. In thisconfiguration, the booms 410 are nearly completely deployed or unrolledfrom the spool 470.

FIG. 7 illustrates a multi-boom deployment device 400 in a deployedconfiguration according to some embodiments. In this configuration, thebooms 410 are unrolled from the spool 470. In some embodiments, thebooms 410 may still be coupled with the spool 470 such as, for example,at the proximal end of the booms 410. The proximal end of the boom 410(e.g., the end of the boom 410 closes to the spool 470) may transitionfrom a flattened state to a tubular state; and each of the proximal endsof the booms 410, for example, may be wrapped around the root plug 425.The root plug 425, for example, may provide structural stability to theproximal end of the boom 410. In some embodiments, the boom 410 may becoupled with the root plug 425 via an additional clamping mechanism thatmay secure the boom 410 with the root plug 425.

Each of the booms 410 of multi-boom deployment device 400 are shownbeing deployed at substantially right angles from the two adjacent booms410. In some embodiments, the booms 410 of the multi-boom deploymentdevice 400 may be configured to deploy at any number of angles, forexample at a 45 degree angle with respect to the side of the housing480. In some embodiments, the booms 410 may be deployed at 90 degreesrelative to one another. Alternatively or additionally, any number ofbooms 410 may be deployed at any number of angles relative to oneanother such as, for example, two booms, three boom, five booms, sixbooms, seven booms, eight booms, etc.

At the end of deployment, the spool 470 may be configured to stopagainst a hard stop and lock in position by the recovered cross sectionof the boom 410. In embodiments including a regained cross-section, theboom 410 may have increased stiffness and strength near the multi-boomdeployment device 400. Such increased strength may also increase thepointing accuracy of a longer and narrower boom 410.

FIG. 8 is a side view of a multi-boom deployment device 400 according tosome embodiments.

FIG. 9 illustrates a single-boom deployment device 900 in a stowedconfiguration according to some embodiments. The single-boom deploymentdevice 900 includes a housing 905 with an openable restraint mechanism910. A spool 920 is disposed within the housing. A boom 915 is flattenedand wrapped around the spool 920. In some embodiments, the boom may becoupled with a sensor 930 and/or a boom wire 925. The sensor 930 may bethe same or similar as sensor 415. The boom wire 925 may be the same orsimilar as the boom wire 465. A root plug 935 may be coupled with thehousing with a spring mechanism 940. The spring mechanism 940 may biasthe root plug so that the root plug 935 may rotate into a positionrelative to the boom 915 in the deployed configuration.

FIG. 10 illustrates a single-boom deployment device 900 in amostly-stowed configuration according to some embodiments. In thisconfiguration, the restraint mechanism 910 has been opened creating anaperture in the housing 905 through which the boom 915 may extend. Thespool 920 may rotate counter-clockwise causing the boom 915 to extend.In some embodiments, the root plug 935 may rotate into the deployedposition as shown in FIG. 10.

FIG. 11 illustrates a single-boom deployment device 900 in amostly-deployed configuration according to some embodiments. In thisconfiguration, most of the boom 915 has been unwound from the spool 920and/or deployed. As the boom 915 deploys, it forms into an extended,tubular shape as shown in FIG. 11. The boom 915 deploys as the spoolrotates counter-clockwise.

FIG. 12 illustrates a single-boom deployment device 900 in a deployedconfiguration according to some embodiments. In the deployedconfiguration, the proximal end of the boom 915 is wrapped around theroot plug 935. The root plug 935 may provide stability to the proximalend of the boom 915. In some embodiments, an additional clamp may becoupled with the boom 915 and/or the root plug 935.

FIG. 13A illustrates a single-boom deployment device in a deployedstate. FIG. 13B illustrates a single-boom deployment device in thedeployed state.

In some embodiments, a boom may include a slit-lock mechanism that mayinclude teeth formed along both side of the longitudinal length of aslit of the tubular boom. FIG. 14A illustrates a plurality of teethalong the length of the slit in an unlocked configuration. FIG. 14Billustrates the plurality of teeth in a locked configuration. In someembodiments, the slit-lock may improve the stability of the boom whendeployed.

In some embodiments, the teeth on the boom may be aligned with keys on aspool when the boom is stowed with the spool. This alignment may allowthe teeth to be engaged to keys on the end caps of a spool as shown inFIG. 15A and FIG. 15B. The slot and key engagement may allow one or morebooms to unspool in a controlled manner such as, for example, atprecisely the same rate every time. In some embodiments, the engagementbetween the teeth and the spool may also allow much higher forces to bedriven from the spool into the boom as it deploys. In some embodiments,the engagement between the teeth and the spool may allow a significantamount of tension to be driven into the boom or booms during deployment.

FIG. 16 illustrates a single-boom deployment device 900 in a stowedconfiguration according to some embodiments. In this example, the boom915 includes a plurality of teeth 926 that engage with keys 921 on thespool 920.

FIG. 17 illustrates the single-boom deployment device 900 in apartially-deployed configuration according to some embodiments. As theboom 915 deploys from the spool 920, a transition zone is created in theboom 915 that is partially between a flattened boom and a tubular boom.This transition zone can be an area were the boom 915 is less rigidand/or weaker.

FIG. 18 illustrates the single-boom deployment device 900 in a deployedconfiguration according to some embodiments. In the deployedconfiguration, the proximal end 960 of the boom 915 is wrapped aroundthe root plug 935. As shown in the figure, the spool 920 includes aplurality of keys 921.

FIG. 19A and FIG. 19B illustrate an example embodiment of a distal endof a boom 1910, which may include similar features as the boom 305, 410,and/or 910. The boom 1910 may include a wire harness 1901. The boom 1910may be configured to control surface voltage potential across thevarious components of the boom 1910, which may include a sphere, aguard, a stub, etc. In some embodiments, control of voltage acrossvarious surfaces may be accomplished by utilizing an insulating layer1905 on the boom 1910, such as polymer scrim at each bondline.

The wire harness 1901 may be configured to be bonded to the inside ofthe boom 1910 and roll up with the boom 1910 upon deployment andretraction. The wire harness 1901 may include the ability to accommodatestorage/deployment cycles. In some embodiments, the wire harness 1901may be routed through the boom 1910 from the internal electronics to thetip of the boom 1910, such that electrical connectivity to thecontrolled surfaces may be achieved with a wire harness 1901. In someembodiments the wire harness 1901 may be a ribbon cable consisting of aplurality of small gauge wires (36-40 awg). In some embodiments, thewire harness 1901 may be a flat flex circuit.

In some embodiments, the boom 1910 may include a conductive surface 1920on the outermost portion of the boom and include an attachment point forelectrical connection to the wire harness 1901. The conductive surface1920 may be atomic oxygen resistant, such as, for example, gold, TiN, orAltiN. In some embodiments, the conductive surface 1920 may be a surfacetreatment or a bulk conductor. Embodiments including a surface treatmentmay include the application of a thin TiN coating. Such embodiments mayapply conductive coatings at relatively low temperatures. Someembodiments may include the application of a bulk conductor to the tipof the boom 1910 as the conductive surface 1920. For example, theconductive surface 1920 may be a thin section of stainless steel bondedto the tip of the boom 1910.

In some situations, measurements such as, for example, DC e-fieldmeasurements can be influenced by the geometry and design of a satelliteand the sensor 415 location. The electrostatic charge of the spacecraftcreates a disturbance in the electric field that may be subtracted fromthe measurement. Therefore, reducing the influence of the spacecraft isdesired to obtain more accurate measurements. In some embodiments, thismay be done by moving the electric field sensor away from the spacecraftbody. In some embodiments, the deployable structure itself may alsodisturb the electric field.

In some embodiments a long and narrow boom may reduce the influence ofthe boom on an electric field sensor. However, some embodiments mayinclude the boom configured with deployed stiffness, natural frequency,and pointing stability sufficient to reduce influence on an electricfield sensor. Some embodiments may include a boom configured to be 2 mlong with a deployed diameter that is less than 20 mm.

In some embodiments a boom may be configured to have a greater deployedstiffness than typical satellite appendages, such as carpenter's tapesprings or conventional slit-tube beams. For example, a boom may includea stability of 1 degree between orthogonal pairs. In some embodiments, aboom may include locking edge features between lateral edges of theboom, sufficient to increase deployed stiffness and improving stabilityin both bending and torsion.

Some embodiments may include compositions configured to increase thermalstability, which may increase instrument performance. For example, solarflux along the boom may result in a temperature gradient across asection of a boom, resulting in increased “thermal bending”, asillustrated in FIG. 20. This phenomenon famously induced “thermalflutter” in the stainless steel slit-tubes of the 1st generation Hubblesolar arrays. However, embodiments of the boom 410 may includematerials, such as graphite composite, configured to have a reduced CTE,increasing the pointing accuracy in large on-orbit thermal gradients. Insome embodiments, the boom 410 may be configured to experience less thana 0.1 degree pointing shift as a result of thermal bending.

In some embodiments the boom 410 and the sensor 415 may be configured tohave a first natural frequency of about 2 Hz.

Modifications may be made without changing the scope of the disclosure.Additional embodiments may also include a magnetometer boom configuredas particle or field sensors that separate from a spacecraft. Additionalembodiments may include a canisterized boom configured to be used as agravity gradient boom, or as a deployable structure to support solararrays, solar sails, antennas, or drag sails. The components andfeatures discussed in the disclosure may be configured to function attemperatures from 4 K to 500 K.

The term “substantially” means within 5% or 10% of the value referred toor within manufacturing tolerances.

Numerous specific details are set forth herein to provide a thoroughunderstanding of the claimed subject matter. However, those skilled inthe art will understand that the claimed subject matter may be practicedwithout these specific details. In other instances, methods,apparatuses, or systems that would be known by one of ordinary skillhave not been described in detail so as not to obscure claimed subjectmatter.

Embodiments of the methods disclosed herein may be performed in theoperation of such computing devices. The order of the blocks presentedin the examples above can be varied—for example, blocks can bere-ordered, combined, and/or broken into sub-blocks. Certain blocks orprocesses can be performed in parallel.

The use of “adapted to” or “configured to” herein is meant as open andinclusive language that does not foreclose devices adapted to orconfigured to perform additional tasks or steps. Additionally, the useof “based on” is meant to be open and inclusive, in that a process,step, calculation, or other action “based on” one or more recitedconditions or values may, in practice, be based on additional conditionsor values beyond those recited. Headings, lists, and numbering includedherein are for ease of explanation only and are not meant to belimiting.

While the present subject matter has been described in detail withrespect to specific embodiments thereof, it will be appreciated thatthose skilled in the art, upon attaining an understanding of theforegoing, may readily produce alterations to, variations of, andequivalents to such embodiments. Accordingly, it should be understoodthat the present disclosure has been presented for purposes of examplerather than limitation, and does not preclude inclusion of suchmodifications, variations, and/or additions to the present subjectmatter as would be readily apparent to one of ordinary skill in the art.

That which is claimed:
 1. A boom deployment system comprising: ahousing; a first spool disposed within the housing; a first boom havinga proximal end, a distal end, and a cylindrical shape extending in afirst direction out of the housing in a deployed configuration, aflattened shape in a stowed configuration, and a slit that extends alonga longitudinal length of the first boom in the deployed configuration,wherein the first boom is stowed in the stowed configuration flattenedand wrapped around the first spool, wherein the distal end of the firstboom comprises a first sensor; a second boom having a proximal end, adistal end, and a cylindrical shape extending in a second direction outof the housing at an angle offset from the first boom in a deployedconfiguration, a flattened shape in a stowed configuration, and a slitthat extends along a longitudinal length of the second boom in thedeployed configuration, wherein the second boom is stowed in the stowedconfiguration flattened and wrapped around the first spool, wherein thedistal end of the second boom comprises a second sensor; a third boomhaving a proximal end, a distal end, and a cylindrical shape extendingin a third direction out of the housing at an angle offset from thefirst boom and the second boom in a deployed configuration, a flattenedshape in a stowed configuration, and a slit that extends along alongitudinal length of the third boom in the deployed configuration,wherein the third boom is stowed in the stowed configuration flattenedand wrapped around the first spool, wherein the distal end of the thirdboom comprises a third sensor; and a fourth boom having a proximal end,a distal end, and a cylindrical shape extending in a fourth directionout of the housing at an angle offset from the first boom, the secondboom, and the third boom in a deployed configuration, a flattened shapein a stowed configuration, and a slit that extends along a longitudinallength of the fourth boom in the deployed configuration, wherein thefourth boom is stowed in the stowed configuration flattened and wrappedaround the first spool, wherein the distal end of the fourth boomcomprises a fourth sensor.
 2. The boom deployment system according toclaim 1, further comprising a restraint mechanism configured to coverthe aperture in the stowed configuration and open in the deployedconfiguration.
 3. The boom deployment system according to claim 1,further comprising: a first root lock disposed within the housing,wherein the root lock is position within the housing relative to thespool, wherein in the deployed configuration a proximal end of the firstboom is wrapped around the root lock.
 4. The boom deployment systemaccording to claim 3, further comprising a spring mechanism coupled withthe housing and the first root lock, wherein the spring mechanism isconfigured to move the root lock from a location in the stowedconfiguration into a position near the spool in the deployedconfiguration.
 5. The boom deployment system according to claim 1,wherein the first boom and one or more of the second boom, the thirdboom, and the fourth boom are substantially orthogonal in the deployedconfiguration.
 6. The boom deployment system according to claim 1,wherein the first boom transitions from the stowed configuration to thedeployed configuration as the spool rotates around an axis, and whereinthe second boom transitions from the stowed configuration to thedeployed configuration as the spool rotates around an axis.
 7. The boomdeployment system according to claim 1, further comprising: a housing,wherein the first spool is disposed within the housing; a second spooldisposed within the housing; and a fifth boom having a cylindrical shapein a deployed configuration, a flattened shape in a stowedconfiguration, and a slit that extends along a longitudinal length ofthe boom in the deployed configuration, wherein the fifth boom is stowedin the stowed configuration flattened and wrapped around the secondspool.
 8. A boom deployment system comprising: a housing having a firstaperture and a second aperture, the second aperture being offset fromthe first aperture; a spool disposed within the housing and configuredto rotate around an axis that is fixed relative to the housing; and afirst boom having a proximal end, a distal end, and a cylindrical shapeextending in a first direction out of the first aperture in the housingat an angle offset from the first boom in a deployed configuration,wherein the proximal end of the first boom is coupled with the spool,wherein the first boom has a flattened shape in a stowed configuration,and a slit that extends along a longitudinal length of the first boom inthe deployed configuration, wherein the first boom is stowed in thestowed configuration flattened and wrapped around the spool, the firstboom transitions from the stowed configuration to the deployedconfiguration as the spool rotates around the axis, wherein the distalend of the first boom comprises a first sensor; and a second boom havinga proximal end, a distal end, and a cylindrical shape extending in asecond direction out of the second aperture of the housing in a deployedconfiguration, wherein the proximal end of the second boom is coupledwith the spool, wherein the second boom has a flattened shape in astowed configuration, and a slit that extends along a longitudinallength of the second boom in the deployed configuration, wherein thesecond boom is stowed in the stowed configuration flattened and wrappedaround the spool, where in the slit in the second boom faces the sameaxial direction as the slit in the first boom; the second boomtransitions from the stowed configuration to the deployed configurationas the spool rotates around the axis, where in the distal end of thesecond boom comprises a second sensor.
 9. The boom deployment systemaccording to claim 8, further comprising a first sensor coupled with thefirst boom and a second sensor coupled with the second boom.
 10. Theboom deployment system according to claim 8, further comprising a firstwire coupled with the first boom and a second wire coupled with thesecond boom.
 11. The boom deployment system according to claim 8,wherein in the deployed configuration the first boom is substantiallyperpendicular with the second boom.
 12. The boom deployment systemaccording to claim 8, wherein the housing includes a first aperturethrough which the first boom extends in the deployed configuration, andwherein the housing includes a second aperture through which the secondboom extends in the deployed configuration.